which is safer

[paradisiac]

ok, so been having a think about all this speedstep stuff.
right well i know its there so that you use less power and generate less heat when you dont need to, so my question is, which is better for the cpu :
1. heating up and cooling down, heating up and cooling down, heating up and cooling down, as you do different tasks with speedstep enabled.
or
2. running at a constant warm temp with speedstep disabled.

wasnt sure if the repeated change in temperatures from 45-75deg would actually do more harm than having it at say a constant 70deg.

 

[JonJ678]

Cycling up and down will encourage thermal fatigue at any joints between dissimilar materials. The processor is unlikely to suffer from this, but the motherboard may well do as I'm fairly sure the socket is soldered to the motherboard. Could take a long, long time though.

Running at a constant higher temperature will encourage electromigration within the processor, but if the temperature isn't particularly high and voltage is reasonable this won't be an issue.

However I'm not sure speedstep makes any difference here though. With it enabled or disabled processor load will vary, so temperatures will vary. Speedstep might exaggerate the size of the temperature change.